1. General Model Information


Acronym: NCSOIL

Main medium: terrestrial
Main subject: biogeochemistry
Organization level: ecosystem
Type of model: compartment model
Main application:
Keywords: nitrogen, carbon, transformation


J.A.E. Molina

Dept. of Soil, Water and Climate
University of Minnesota
St. Paul, MN 55108, USA
Phone: 612 625-6259
Fax : 612 625-2208
email: GVB6082@VX.cis.umn.edu



NCSOIL is a theoretical process model of nitrogen and carbon transformations in soil. NCSOIL is a sub-model of the NCSWAP model. It computes the short- and long-term dynamics of carbon and nitrogen organics, ammonium, and nitrate which result from the processes of residue decomposition, mineralization, immobilization, nitrification, and denitrification.

The model computes the changes in organic forms of C and N, exchangeable plus soluble ammonium, and nitrate concentrations which result from the processes of residue decomposition, mineralization, immobilization, nitrification, denitrification, and nonsymbiotic N fixation. These transformation rates are soil water and temperature dependent. A mechanism is included to account for the increase in mineralization following a physical disturbance (tillage) of the soil.

The model is built on the concept of catenary sequence of heterogeneous substrates. The soil organic C and N substrates are defined by their kinetic rate constants and their position in the model's structure. Residues are defined in terms of their chemical, or morphological, characteristics. Eight C and N pools are considered: the organic residues, pool I and pool II of the soil active organic phase, pool III of the stable organic phase, exchangeable plus soluble ammonium, nitrate, dinitrogen, and carbon dioxide. Summation of the rates is performed by the Runge-Kutta method.

Author of the abstract:


II. Technical Information

II.1 Executables:

Operating System(s):

II.2 Source-code:

Programming Language(s):

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

J. A. E. Molina, C. E. Clapp, M. J. Shaffer, F. W. Chichester, and W. E. Larson. 1983 NCSOIL, A Model of Nitrogen and Carbon Transformations in Soil: Description, Calibration, and Behavior. Soil Science Society of America Journal. Volume 47, no. 1.
Nicolardot, B. and J. A. E. Molina. 1994 C and N Fluxes Between Pools of Soil Organic Matter: Model Calibration with Long-Term Field Experimental Data. Soil Biol. Biochem. Vol 26, NO. 2, pp 245-251.
Aviva Hadas and J. A. E. Molina.1993 Simulation of Nitrogen Assimilation by Heterotrophic Soil Microbial Biomass. Physiologia Plantarum 89: 664-668.

V. Further information in the World-Wide-Web

VI. Additional remarks

Last review of this document by: R. Patzak : 17. September 1997
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:46 CEST 2002

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